* Arsenal beat West Bromwich Albion 1-0
* Giroud strikes late to seal victory
* Giroud scored fourth league goal of season in first league start
* Albion goalkeeper Foster had denied Arsenal with three top saves
* Yacob spurned rare chance for visitors
* Gunners are nine points behind leaders Chelsea
* Arsenal host Crystal Palace next, West Brom visit Southampton
Dec 26 (Reuters) - Olivier Giroud made the most of his first league start of the season by heading Arsenal to a 1-0 win over West Bromwich Albion on Monday and avoiding a third game without victory for Arsene Wenger's side.
Goalkeeper Ben Foster had repeatedly frustrated the hosts in a dominant second-half display but France international Giroud finally found a way through by nodding Mesut Ozil's arched cross beyond him in the 86th minute.
Giroud's fourth league goal of the season lifted Arsenal third in the standings, level on 37 points with Liverpool who play Stoke City on Tuesday, but they are still nine behind leaders Chelsea.
Arsenal came alive after the break following a timid first- half display but kept coming up against the heroic Foster, who denied Alex Iwobi and Alexis Sanchez, who also rattled the post.
Reporting by Richard Martin, editing by Ed Osmond